The game shifts away from standard Kanto storylines to deliver a concept-driven campaign set on Shuckle Island. Located far from the rest of the Pokémon world, the island is a closed nature preserve where only a single species of Pokémon has ever inhabited: Shuckle. Over several generations, the original Shuckles adapted to the varied local climates of individual routes, giving rise to dozens of distinct regional breeds while the original, standard form went extinct.